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Not sure if this belongs in the Off Topic ....
I have several flasher batteries and I want to know how good they are. I know they will charge to full, but I recall the end of last ice season there were a few times that the batteries would be very low or dead before I finished the day on the ice. In the past my experience has been that they last longer than a full day on the ice....usually have lasted two trips before needing a charge.
I purchased a multimeter but I have no clue or knowledge about Volts/Watts and what they all mean.
I have a few examples
On a fully charged battery lets say it will read 12.80. When I add juice to it and test it will go up a little higher....into the 13's.
When I turn on the flasher and test it will drop to 9.37.
On another fully charged battery it will read 12.80. Adding juice will push it up higher.
When I turn on the flasher it will remain at the 12.80 but about every 3-5 seconds it will loose one point....12.80, 12.79, 12.78, 12.77...etc.
I have not done the math to determine just how long that will last until there isn't enough power left in the battery to run the machine.
Should that number be dropping that fast?
Overall question - how can I tell which of my batteries are still in excellent condition and which ones I need to replace?
If it makes any difference I have them in a Vex 18, Vex 28, and Humminbird 55.
Thanks!
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[#0000FF]I assume you are talking about the little 12 volt SLA (sealed lead acid) batteries.[/#0000FF]
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"[#0000FF][#000000][size 3]In the past my experience has been that they last longer than a full day on the ice....usually have lasted two trips before needing a charge." [/size][/#000000][/#0000FF]
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[#0000FF]First of all, they are not originally intended to be "deep cycle" batteries...running them to failure before recharging. But that is the best shot we have for a small battery for sonar applications.
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[#0000FF]Probably the single most important factor...for long life and good output is to charge them fully before each use and then again as soon as you get home from a trip. Use a small .5 to .8 amp trickle charger and not a high amp charger for auto batteries.[/#0000FF]
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[#0000FF]Try to get a charger with an indicator light to show when the battery is charged...or one that maintains the battery at full charge when not in use. Also, instead of a multimeter, get a simple voltage tester.[/#0000FF]
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[#0000FF]Most good SLA 12 volt batteries will show over 13 volts when fully charged. But most will maintain a "resting charge" of about 12.7 volts. If your battery drops much below that in a short time after a full charge you probably need to replace it. They last several years with proper use and maintenance but they all fail...especially when completely drained before charging and when allowed to sit uncharged for long periods.
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[#0000FF]There is a lot of difference in how much juice a sonar sucks from your batteries. Some can run all day on a 7 amp/hour battery. Others need at least a 9 a/h or higher. Always a good idea to carry an extra for long days on the ice...and to not run them clear to failure before replacing with a fully charged one.[/#0000FF]
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[#0000FF]Like all batteries, SLA batteries last longer and have better output if kept warm. Cold kills batteries. So if you can keep your battery in an insulated container...maybe with a hand warmer packet...you will get longer life on cold days.
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Quit the gambling & guessing games. Check out Dakota Lithium batteries and buy one of those. 2,000 cyclers, powerful & light as a feather. Had trouble with the
Helix 7 on the bow of my Crestliner this summer, shutting off 'cuz of the small guage wires going all the way back to the stern. Yanked those and put a Dakota Lithium (12v 10ah) in my bow storage area and have never looked back. This winter I'll use the same battery in my Genz box with my Helix 5. Even bought a smaller one to
drain the water off my pool cover. Only way to go.
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Like Tube Dude says, it's important to not drain the battery way down and to keep it charged up. My sonar has a voltage indicator on the screen so I know when it's time to change the battery. Even though it will still run on 10 volts, that is not good for the battery life. However, the batteries are so cheap online that I prefer to just replace it when it starts taking a dive rather than packing multiple batteries out on the ice to make it through the day. I've had good luck with the no-name Chinese batteries that you can buy on e-bay for less that 15 bucks shipped.
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Allow me to emphasize the point about fully discharging.
Lead-acid batteries suffer damage when fully discharged, a little if you're lucky, and severe if you're not. That damage prevents it from ever accepting or holding a full charge again.
Glass mat (AGM) batteries may be less susceptible to that damage than liquid cells. Repeat MAY. But don't count on it.
Lithium is indeed the way to go if you can afford one.
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A good battery will measure about 12.8V. If sitting for a month or so it may drop to 12.6 or 12.7V. No worry just normal. Charge it back up and good to go.
Your batteries dropping 0.01 (10mV) or so is no concern. When you measure it with the volt meter, it will be try to accurately measure the voltage but it may be off slightly a bit plus or minus.
After fishing for 8 to 10 hours or so the battery could start get down low enough and your electronics will start to not like the low battery voltage and if too low the electronics will turn off.
The battery you talked about at 9 or 10V is toast.
Hope that helps.
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Unfortunately you cannot rely on a voltage reading to determine the quality of a battery, a load test will be needed.
If it was a car battery I could help you.
Maybe a store like Batteries Plus could help you?
Good luck!
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Batteries plus probably could help actually. If you're not charging them up every couple months during the off season and they lose their full charge and sit that will kill them. That doesn't mean to keep them on a trickle charger for a long period of time though. Lead acid batteries can also be reconditioned to at least a percentage of new capability but it takes a reconditioner or at least a charger that can be set to charge it slowly over the course of a day, day and a half. It's not guaranteed.
Lithium doesn't like being 100% charged all the time while lead doesn't have as much of a problem with it. No batteries do good being completely dead of course.
I like to charge my ice season batteries when I do other stuff that happens yearly, so it's sure to happen every couple months.
Don't bet your safety on a reconditioned battery though. Also, that battery you're talking about is a goner, like others have said. No need to go out and get a fancy charger for that one.
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[font "Comic Sans MS"][#800000][size 3]You might find the following links of interest:[/size][/#800000][/font]
[url "https://batteryguy.com/kb/knowledge-base/what-is-the-shelf-life-of-a-sealed-lead-acid-battery/"][size 3]What is the shelf life of a sealed lead acid battery?[/size][/url]
[url "https://www.power-sonic.com/wp-content/uploads/2018/12/Technical-Manual.pdf"][size 3]SLA Battery Tech Manual[/size][/url]
[font "Comic Sans MS"][#800000][size 3]I don't know what specific batteries you have, but the current crop of batteries coming with the Vexilar FLX28 are DEEP CYCLE and will withstand up to 1,000 discharges dependent on the depth of the discharge. Vexilar has a prorated warranty of 2 years on their batteries. My FLX28 is starting its 3rd season with 2 trips already in the bag (Trial lake last month).[/size][/#800000][/font]
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[font "Comic Sans MS"][#800000][size 3]I store my FLX28 in the house and do not charge it at all during the storage even though that is the recommendation. It is fully charged and switched off when going into storage. When it comes out of storage, it is again fully charged before using it.[/size][/#800000][/font]
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[font "Comic Sans MS"][#800000][size 3]I don't recharge it until the low battery alarm indicates it is getting low. This generally happens about every 4 or 5 trips. The battery is still going strong and my previous FL12 lasted 5 years on the original battery following the same process.[/size][/#800000][/font]
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[font "Comic Sans MS"][#800000][size 3]It certainly doesn't hurt a thing to recharge after every trip using the charger that came with the unit. And recharging it once during the storage period, while not required, is recommended.[/size][/#800000][/font]
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[font "Comic Sans MS"][#800000][size 3]Find a Batteries Plus store or a National Batteries store near you and have them load test your batteries. That is the only way to determine their condition without buying specific battery testing electronics which isn't very cost efficient.[/size][/#800000][/font]
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Bob Hicks, from Utah
I'm 82 years young and going as hard as I can for as long as I can.
"Free men do not ask permission to bear arms."